Patent GB-486997-A (GB)
Title: A machine for drawing wire or strip
IPC: B21C1/12
Filed: 1937-06-12
Abstract: 486,997. Drawing wire. BRETTELL, F. G. (National Standard Co.) June 12, 1937, No. 16370. [Class 83 (iv)] In a machine for drawing wire or strip of the type wherein the drums are driven at a speed controlled by the tension of the wire in advance of the dies, the material is fed downwardly in a substantially vertical direction through the die, the drum being below and in alignment with the die. A wire-drawing machine comprises a number of units each comprising a drum 4 driven by a motor 6 of the constant speed type and a die 8. Each drum 4 is driven by a herring-bone gear 28 from a pinion 30, a planetary speed reducer 32, and a pulley 34 driven by a belt 36 from the motor 6. A variable speed pulley on the motor shaft comprises a fixed cone 40 and a cone 42 slidable with respect thereto under the action of a spring 43. Variation in the speed of the drum is produced by moving the motor to vary the distance between the pulleys 34, 38, the motor moving along an inclined way 48 so that it simultaneously moves laterally to keep the cones 40, 42 symmetrical with respect to the belt. Drums; lubricating and cooling ; die-holders. -The drum comprises flanges 52 merging by curves of wide radius into the peripheral surface. A rubber roller 58 bears on the wire on the drum, being mounted on a bell-crank lever such that it may be held against or away from the wire by a spring 63. Water is circulated to a jacket 54 by an inlet 56, a tube 377 and a tube 386, and is discharged through a tube 387, the bore 376 of the drum, and the pipe 388. A partition 385 is secured between the tubes 386, 387 in the jacket 54. The die-holder 10 is bolted to the machine frame, the die 8 being secured in a block 158, supported by the holder 10, by a threaded sleeve 156. The block 158 is adjustable horizontally, and may be adjusted at an angle to the horizontal by set screws 160 if the bore of the die is not accurately perpendicular to the die faces. The die block which is made of copper or other material of high heat conductivity has passages 389 for the passage of cooling water. A lubricating soap container adapted to slip on the sleeve 156 comprises a bin 162 from which soap passes to a chamber 166 through which the wire is led. Deteriorated soap may thus be removed from the chamber 166. A slide 168 closes the lower end of the container when it is to be removed. A die-holder 10, Fig. 9, is adjustable by screws 214 about trunnions 212. Tensioning.-The speed of each drum is controlled automatically to keep a constant tension in the wire. The wire passes over a pulley 72 on a vertically movable slide 70 which is counterbalanced by a weight 80. The slide carries a member engaging a spiral slot 104 in a tube 102, variation in the tension of the wire causing the slide to move up or down thereby rotating the tube 102, and, through worm-gearing 118, and links 124, 126, 128, 132 136, altering the position of the motor 6 to vary the speed of the drum and restore the correct degree of tension. The range of speed is varied by employing different holes 138 for a pivot pin 140, and by varying the effective length of the link 126 by a screwed adjusting wheel 146. The link 126 includes a tube 150 through which the movement is transmitted by springs 154, permitting the slide 70 to move rapidly independently of the inertia of the motor, and speeding up the movement of the parts of the pulley 40, 42. A pawl 86 is normally held from a rack 84 by the tension of the wire passing over a pulley 94, but is moved by a spring 96 to engage the rack if the wire breaks, to prevent the sudden rise of the slide 70. The speed of the first unit is adjusted by a handle, the remaining units automatically assuming the correct speed. The winding-up reel 174, Fig. 7, is driven from the final drum 4 by a belt 190, the tension of which is varied by movement of a roller 198 in accordance with the variation in tension of the wire, from a slide 70 similar to that employed for controlling the drums. In a modification, Figs. 9 and 11, a slide 70 is slidable on rollers on the vertical guides. The motor 6 is mounted on a pivoted arm 218 which is swumg to vary the speed of the drum by means of a variable speed pulley 38. The arm is swung on movement of a rack-bar 226 by the slide 70, the bar engaging a toothed sector 230 which rocks a gear 234 to move the arm through a chain. The weight of the motor and additional weights 219 determine the tension of the wire. Pawls are released to engage safety racks if the wire breaks. A slide-mounted tension controlling device for the last unit comprises a series of rollers 262, over which the wire passes, supported between plates 260 and adapted to swing about a vertical pivot. Reeling and supplying a wire.-The winding-up reel 174 has a central bore 286 engaged by stub shafts 288, 290. The stub shaft 288 is moved into engagement with the bore by a screwed shaft actuated by a hand-wheel 298. The shaft 290 carries driving projections 306 engaging holes in the side of the reel, and is moved axially by a lever 310. The drive is effected through a ratchet wheel 322 and pawls 324, permitting actuation by hand for taking up slack or aligning the driving projections. The reel is raised to position by a cradle actuated by a pedal 338. A similar mounting may be employed for the supply reel, which is not driven but is checked by a brake controlled by a pulley in accordance with the tension of the wire. The final pulley 72, Fig. 7, is mounted on an arm 176 swinging about a vertical pivot 178, to permit the wire to be fed to the reel 174 by a level winder 182, Fig. 10. The winder comprises a right and left-hand threaded shaft 350 rotated by a belt 184 to reciprocate a sleeve 354. The wire guide is carried by a further slide movable relatively to the sleeve 354 to vary the traverse of the guide. A pin 362 depending from the slide engages the forked end 363 of a bell-crank lever 365 pivoted at 364 to the sleeve 354. A pin 366 on the lever engages a slot in a bar 370, bodily movement of the bar by screws 372 moving the limits of movement of the guide to right or left, while an angular movement of the bar varies the distance traversed by the guide.